Q.How Could I Fix My Moon Cactus With A Tear In The Stalk?
The stalk looks more of a brownish green than dark green, and besides the tear the root system doesn’t seem to be rotted.
Certified GKH Gardening Expert
Unfortunately, your photos did not come through. I am unable to see the state of your cactus. Unfortunately, if the color is continuing to change, then you might assume that the rootstock is dying off. If this is the case, then you may need to graft the top onto another. They do graft, rather, easily!
Here is an article that will help you with their care: